Simple Mixed Model Scheduling

Mixed-model scheduling is a highly visible change in the Production scheduling of the products with different models or specifications. The product range is wide and extends from Paints, Chemicals, Paper, Engineering, Plastics, Synthetic Yarn, Consumer goods, Food and Plastic products etc.
Prior to MMS, the conventional approach in most companies has been to “batch-build” products to gain the cost advantage that has come with large batch quantities. MMS however, forces us to minimize the batch sizes, while sacrificing neither productivity nor incurring extra costs.
Mixed model scheduling works like this. If there were three products being built – Product A was 50 percent of total volume, Product B was 25 percent of the volume and Product C the remaining 25 percent, a company would attempt to schedule these three each day as follows:

Day 1 Day 2 Day 3

A,B,A,C A,B,A,C A,B,A,C

Obviously, every other product is the popular one and the other two are interwoven.
There are two incentives for doing this, externally to the customer and internally to the factory and suppliers. The advantage externally is that by making products frequently, you can offer quick delivery to marketplace without having to carry the sizeable finished goods inventory.
MMS reduces the customer – response time up to 80%
Prior to MMS, in the anxiety building higher batch sizes, a Production schedule will include firm-order with yet to be booked orders. Besides increasing customer response time, the earlier approach creates a crisis when the “Yet to be booked” orders do not materialize and other models get booked. This triggers a chain of mutual retributions between marketing and Production. Such situations are the cause of continuing functional confrontations and non-co-operation.
A JIT company normally always builds what customer need, rather than periodically building batches. This is accomplished first by reducing lead times and cycle times. This reduces the time for model to model change to almost one forth. The system improves the sales opportunities due to better customer response time.

Source : Tushar Kulkarni - Accenture